Abstract: In order to investigate the mechanical behavior of newly developed materials such as
bulk amorphous metals, it is essential to use small-size specimens. An instrumented impact testing
apparatus was devised which could provide a load-displacement curve on subsize Charpy
specimens under impact loading without oscillations. The impact fracture behaviors of Zr-based
bulk amorphous metals (BAM) were investigated by using the instrumented impact tester using
both V-notched and precracked subsize Charpy specimens. It was found that most of the fracture
energy absorbed was used in the process of crack initiation through the development of shear bands.

Abstract: The thermo-mechanical fatigue (TMF) behaviour of the Nimonic 90 Nickel base
superalloy has been investigated within two laboratories. In-phase-tests (IP) where the maximum
mechanical strain occurs at the maximum temperature (850°C), and 180°-out-of-phase-tests (180°
OP) where the maximum mechanical strain coincides with the minimum temperature (400°C) have
been applied. All tests were carried out at varying mechanical strain ranges with a constant strain
ratio of Rε = - 1. A temperature rate of 5 K/s was used throughout the whole cycle without any
additional cooling system during decreasing temperature. The fatigue life of 180° OP tests is longer
compared to identical IP tests. The stress / mechanical strain hysteresis loops are completely
different and some characteristic values are compared to each other. The fracture surfaces observed
show that fatigue crack (or cracks) starts on the external surface and propagates inwards. The
fractures of 180° OP tests are transgranular showing the presence of fatigue striations, while the
fractures of IP tests are mixed transgranular and intergranular with no fatigue striations.

Abstract: A material family to replace the current superalloys in aeronautical gas turbine engines is considered to be that of gamma Titanium Aluminide (-TiAl) alloys. Structural components in aeronautical gas turbine engines typically experience large variations in temperatures and multiaxial states of stress under non-isothermal conditions. The uniaxial, torsional and bi-axial thermo-mechanical fatigue (TMF) behaviour of this -TiAl alloy have been examined at 400 – 800oC with strain amplitudes from 0.15% to 0.7%. The tests were conducted at both in-phase (IP) and out-of-phase (OP). The effects of TMF on the microstructure were also investigated. For the same equivalent mechanical strain amplitude uniaxial IP tests showed significantly longer lifetimes than pure torsional TMF tests. The non-proportional multiaxial OP test showed the lowest lifetimes at the same equivalent mechanical strain amplitude compared to the other types of tests.

Abstract: High temperature testing of cement mortar containing bottom ash (BA) generated by municipal solid waste incineration (MSWI) as partial replacement of natural aggregate is presented in the paper. The measurements of mechanical properties, bulk density, matrix density, and total open porosity are performed on samples exposed to the temperatures of 20°C to 1000°C. TGA analysis is performed as well. Finally, the studied samples are analyzed by IR spectroscopy in order to evaluate TGA data. The obtained results indicate a comparable performance of the mortar modified by BA with the reference material.